By James Kilner TBILISI, Nov 12 (Reuters) - Georgia's leaders are reeling from the biggest challenge yet to their power, and the driving force behind it is a moustachioed multi-millionaire wanted in Russia on fraud charges. Badri Patarkatsishvili, Georgia's richest man, galvanised a series of protests against President Mikhail Saakashvili this month that ended with police closing down the tycoon's television station and using tear gas on protesters. Now 52-year-old Patarkatsishvili -- instantly recognisable by his mane of white hair and extravagant moustache -- says he will run against Saakashvili in an early presidential election called to defuse the standoff. Whatever the outcome of his presidential bid, the turmoil of the past few weeks has catapulted Patarkatsishvili out of the shadows and into a key role in Georgian politics. It has also cast a spotlight on his colourful biography. The thread that runs through the businessman's career is his friendship with Boris Berezovsky, the Russian tycoon who wielded huge political influence in the 1990s and now lives in self-imposed exile in London. "If you're very rich and own a television channel you can do an awful lot," said Alexander Rondeli, head of the Georgian Foundation for International and Strategic Studies think-tank. "Patarkatsishvili has a chance and will be a threat." Saakashvili ended the protests by declaring a state of emergency and ordering a crackdown that left his image as a champion of democracy in tatters. Prosecutors named Patarkatsishvili as a suspect in a coup plot. "Mr Saakashvili's regime has completely discredited itself in the eyes of the Georgian people," Patarkatsishvili said. DOUBLE ACT Patarkatsishvili -- whose name means "son of a little man" -- made his fortune in Russia during the chaotic period after the Soviet Union folded when state property was being sold at bargain prices in rushed privatisations. Alongside Berezovsky, Patarkatsishvili's business interests included AvtoVaz <AVAZ.MM>, Russia's biggest car manufacturer, the oil company Sibneft <SIBN.MM> and aluminium firm Rusal. When Berezovsky and Patarkatsishvili were charged in Russia with fraud, both left the country. They no longer own major stakes in the Russian firms. Berezovsky says Russia fabricated the charges against him and his partners because he fell out with President Vladimir Putin. Berezovsky sold Kommersant, one of Russia's most respected newspapers, to his Georgian business partner. Patarkatsishvili last year sold the daily on to Alisher Usmanov, a metals magnate with Kremlin connections. The Georgian businessman has struck a deal with global media magnate Rupert Murdoch, under which Murdoch's News Corp. <NWSa.N> became co-owner of the Imedi station. Patarkatsishvili's election bid will be a lonely affair. He will draw no support from Georgia's opposition coalition, which has named 43-year-old Levan Gachechiladze, a wine entrepreneur and member of parliament, as their candidate. Many observers say Patarkatsishvili will struggle to win high political office. "He has no chance," Nana Sumbadze, from the Institute for Policy Studies in Tbilisi, said. "He is not backed by any party, is not popular and has a dubious reputation." Many Georgians say in private he cannot win high office because he is Jewish in a country where voters like their leaders to belong to the majority Christian Orthodox faith. His supporters say he would be a better leader than Saakashvili. Others say he is too much of an unknown quantity. Certainly his assumption of high office in Georgia would further darken the clouds hanging over relations between Tbilisi and former Russian imperial masters to the north. "What are his policies? What is his vision for Georgia? Where does he want to take the country?" said a middle aged man walking past Tbilisi's parliament building on Monday. (Editing by Ralph Boulton)